Construction equipment, such as earth-moving vehicles and the like, must be stabilized during construction or digging operations to limit movement of the equipment or vehicles. Typically, stabilization is provided by hydraulically actuated arms that extend from the vehicle and that have earth-engaging pads mounted on their distal ends. When the vehicle or equipment is moved into a working position, if extra stability is needed, the stabilizer arms are hydraulically operated to move from a retracted position, in which the arms generally extend upwardly and out of the way, to a user position in which the arms extend downwardly at an acute angle to the ground surface so that the pads contact the ground surface. When it is desired to move the vehicle, the arms are returned to the retracted position, and the vehicle is moved to a new operating location.
Reversible stabilizer pads for construction equipment, such as earth-moving vehicles and the like, are well-known in the prior art. Examples of such pads are found in U.S. Pat. Nos. 4,761,021; 4,889,362; 5,992,883 and 6,270,119. Such stabilizer pads generally have a first surface for engagement with a softer surface, such as gravel and soft earth, and a more resilient second surface on the opposite side of the first surface for engagement with harder surfaces, such as concrete or asphalt. Typically, the first surface includes flanges with grouser points that permit the pads to dig into the softer, unfinished surface formed by gravel or soft earth, to better anchor and stabilize the vehicle when encountering difficult digging conditions. The first surface is unsuitable for contact with a hard surface, since the grouser points could damage or mar the hard asphalt or concrete. The second surface of the pad typically is formed of a laminated, rubber pad for better stability on the more solid surface provided by concrete or asphalt. The stabilizer pad typically is pivotally mounted to the distal end of the hydraulically operated arm so that the pad may be rotated to contact the ground with either the first surface or the second surface.
U.S. Pat. No. 4,889,362 discloses a reversible stabilizer pad for earth moving vehicles having a generally flanged first surface for engagement with, for example, gravel and soft earth, and a resilient surface for engagement with, for example, concrete or asphalt. This patent describes the use of rubber pads on one side of the stabilizer pad for ground contact when the vehicle is on a finished surface, such as concrete or asphalt, and flanges with grouser points on the opposite side of the stabilizer pad for ground contact when the vehicle is on an unfinished but hard ground surface that requires that the pads dig into the surface in order to better anchor and stabilize the vehicle when encountering difficult digging conditions. The flange side of the pad is unsuitable for contact with a finished surface since it could damage and/or mar the finished surface. The stabilizer pad is pivotally mounted to the end of a hydraulically operated arm such that the pad may be rotated to contact the ground with either the rubber pad side or the flange side facing down to contact the ground surface. When the vehicle is moved into a working position, if extra stability is needed, the stabilizer arms, on which the pads are mounted, are hydraulically operated to move from a retracted position, in which the arms generally extend upwardly and out of the way, to a use position, in which the arms extend downward at an angle with the pads contacting the ground surface. When the vehicle is to be moved, the arms are lifted back to the retracted position, the vehicle is moved to a new operating location and the stabilizer arms are brought down into the use position again, if necessary.
Reference is also now made to co-pending application Ser. No. 11/726,226 filed on Mar. 21, 2007 and describing further improvements to a stabilizer pad, particularly relating to providing a more economical pad and one that is both lightweight and durable. In this pad structure the main metal plate member is formed using certain bending steps so as to minimize the welding of components.
It is an object of the present invention to provide still further improvements to stabilizer pads to enhance their durability, to enable them to be manufactured more economically and to enable effective stability thereof even with a lighter weight construction.